There was a fire in LG Chem’s plant in South Korea in March of this year. “So what?”  you might ask. Well, that plant makes lithium-ion batteries, and that’s helping to limit the supply of laptop computers. “I think maybe the battery shortage may hurt every brand,” said J.T. Wang, chairman of Acer, at the company’s investor conference two weeks ago.But the head of the world’s largest independent notebook battery maker, Simplo Technology, said he expects the lithium-ion supply to return to normal in the